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Biomedical subjects

C Dekker

Publications and source records attributed to C Dekker.

At least 55 records · Page 3Linked to original sources
PubMed1993

Unrecognized pertussis infection in adolescents.

Little information is available regarding the level of immunity to Bordetella pertussis among adolescents. We measured serum antibodies in 156 healthy adolescents to the following pertussis antigens: pertussis toxin, filamentous hemagglutinin, and 69-kd outer membrane protein. In an attempt to identify intercurrent pertussis infections, we also obtained a total of 43 repeated samples during the following 5 years. Using a 50% or greater rise in IgG enzyme-linked immunosorbent assay titers to define seroconversion, we found an annual incidence of 6.1%; by alternative definitions of seropositivity, the predicted annual incidence of infection ranged from 1.2% to 8.2%. These data suggest that infection with B pertussis is common in the adolescent population.

Adolescent↗
PubMed1993

Pilot evaluation of influenza virus vaccine (IVV) combined with adjuvant.

The safety of licensed influenza virus vaccine (IVV) combined with a novel adjuvant containing muramyl tripeptide (MTP) conjugated to phosphatidylethanolamine (PE) was evaluated in a randomized pilot study. Ten healthy 23-30-year-old men were given a single intramuscular dose of IVV combined with saline (n = 5) or with 100 micrograms of MTP-PE in the MF59 adjuvant emulsion (MF59-100) (n = 5). Evaluations were performed on days 0, 1, 2, 4, 7 and 28 after inoculation. IVV alone was well tolerated. All volunteers immunized with IVV/MF59-100 experienced moderate to severe local and systemic reactions which interfered with usual activities. Discomfort at the injection site was first noted at 2-6 h; induration (5/5), erythema (3/5), and regional adenopathy (3/5) persisted for up to 4 days. Systemic symptoms including chills (5/5), fever (3/5), nausea (3/5) and/or dizziness (2/5) developed within 12 h of inoculation and resolved by 48 h. Elevated white blood cell count (days 1 and 2), erythrocyte sedimentation rate and serum fibrinogen were transiently observed. Although peak serum neutralizing antibody titres versus influenza A/H3N2 and influenza B antigens were higher in the group given IVV with MF59-100, these unexpected reactions indicate that this dose of adjuvant is unsuitable for use in combination with this IVV.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1991

Childhood asthma and the indoor environment.

To investigate the influence of indoor air quality on respiratory health, a questionnaire-based study of 17,962 Canadian schoolchildren in kindergarten through grade 2 was carried out in 1988. The present report focuses on associations between several indoor environmental factors and childhood asthma. Increased reports of physician-diagnosed asthma were significantly associated (p less than 0.001) with exposure to environmental tobacco smoke (OR = 1.4), living in a damp home (OR = 1.5), the use of gas for cooking (OR = 2.0) and the use of a humidifier (OR = 1.7). Wheezing without a diagnosis of asthma also was associated (p less than 0.01) with environmental tobacco smoke (OR = 1.4, home dampness (OR = 1.6) and humidifier use (OR = 1.4), but not with gas cooking. Thus, several modifiable risk factors for respiratory illness may exist in Canadian homes. Further research is required to determine the nature of these cross-sectional observations.

Air Pollution, Indoor↗
PubMed1989

Allergic arthritis induced by cationic proteins: role of molecular weight.

Previous studies have shown that chronic murine allergic arthritis can only be induced with cationized BSA, related to excellent retention of the cationic antigen in the joint. We now investigate the impact of size of cationic proteins on their potential to induce this form of arthritis. After intra-articular injection, antigen retention is much enhanced with high molecular weight cationized proteins, like albumin or immunoglobulin, compared to small-sized proteins like myoglobulin and lysozyme. Consequently, severe chronic arthritis was only found with the former ones. The role of size is further substantiated with poly-L-lysine-coupled lysozyme. This derivative shows excellent retention in vivo and causes a chronic destructive arthritis in preimmunized mice, in contrast to the poor arthritis seen with native cationic lysozyme. Control experiments made it clear that antigen retention is the most important denominator and that differences in chronicity are not related to gross variations in T-cell reactivity. Retention studies in vitro revealed that the potential to bind to joint structures is similar for the various proteins, suggesting that in vivo conditions determine size-related differences in antigen clearance. Our data indicate that cationicity per se does not make a protein a proper arthritogen.

Animals↗
PubMed1983

Virus resistance in clinical practice.

The sensitivity to acyclovir of more than 800 herpes simplex virus (HSV) isolates from over 300 patients were tested by the dye-uptake method. While a broad spectrum of sensitivity was found, approximately 90% of the isolates were inhibited by less than 1 mg/l of acyclovir. Therapy usually did not significantly alter the sensitivity of HSV isolates except in a few severely immunocompromised patients in whom resistant viruses produced asymptomatic or indolent infections. The sensitivity of viruses isolated during subsequent recurrences was similar to that of the originally infecting virus, regardless of therapy. The requirement of convenient and standardized methods of virus sensitivity testing is emphasized so that additional data can be accumulated to allow more precise correlations between in-vitro virus sensitivity and clinical response to acyclovir therapy.

Acyclovir↗
PubMed1981

Human body fluid ribonucleases: detection, interrelationships and significance.

Study of the RNases of human body fluids has been facilitated by use of activity staining following SDS-polyacrylamide gel electrophoresis. Commercial SDS preparations contain minor lipophilic contaminants (less than 0.1%) which interfere with enzyme renaturation and prevent activity staining unless gels are washed after electrophoresis in 25% isopropanol. Partial characterization of the RNases of serum, urine, and cerebrospinal fluid (CSF) is described, including evidence that the RNases comprising bands A-C of urine and 1-3 of CSF are glycoproteins. Evidence is presented that the major RNase activities of serum (RNases 1-5) and urine (band A) do not originate in pancreas, and that leukocytes are the source of band D RNase of urine, as well as of minor RNase activities of serum and CSF. Results are summarized suggesting that elevated plasma RNase levels may be of dubious utility in the diagnosis of most malignant diseases. Some elevated levels reported in the literature may reflect the advanced age of cancer patients, negative nitrogen balance, and other secondary effects of diseases, particularly kidney dysfunction.

Clinical Enzyme Tests↗